Process of manufacturing chamotte materials



.Patentecl Apr. 3,1928 I I 1,ti64:,(i89 UNITED STATES PATENT OFFICE.

mmwre Klimt, or BALTIMORE, MARYLAND.

PROCESS OF MANUFACTURING GHAMOT'IE MATERIALS; No Drawing. 7 Application filed October 13, 1925. Serial No. 62,307.

The present invention relates to the manuand irregular in composition and property. facture of chamotte of particularly high In accordance with the present invention,

grade, having valuable physical and chem- I have found it possible to overcome the said ical properties, and relates particularly to difiiculties by using woody substances, which 60 the manufacture of the grog to be used in are employed in finely divided state and making such chamotte. which are consumed during the burning of As is well known in the art, it is customary the gro leaving the latter-porous. To the to form plastic clay into sheets, bricks and materia s used in the preparation of'th'e the like,to then burn the same at ahigh'temgrog I also add a cementitious agent, such 65 10 perature, after the plastic material has been as Portland cement, natural cement, magnedried, and to thereafter crush the burned sium chloride or oxychloride, precipitated material to a granular form, and to then magnesium silicate or ball clay, or materials mix the granulated material withthe neceswhich form cement during the heating op-" sary amount of plastic clay and form the eration or during the moistening o era- 79- same into blocks, slabs or other shaped artion. Kaolin in an unburned con ltion ticles, and to then burn the same. Products forms the basis (or major constituent) of the made in this mannerare ordinarily termed grog material, and to this is added from 5 chamotte and are used in various indi1s to 25% of Woody substance and about the tries where it is desirable to employ high same amount of the binder, water of course 75 temperatures. Thus mufiies, and various being used in amount sufficient to form a pots for use in metallurgy are commonly plastic mass which is then burned as in the made in the art. prior art, after which the burned material In order to obtain good quality of grogs, in the form bricks, slabs or the like is clay alone is sometimes used, but on account crushed up, and on account of its texture it 90 of its tendency to shrink at high temperacrushes easily 'to a granular mass of the detures, as well as being subject to chemical sired size, in contradistinction to the grog changes, clay does not'give satisfactory resubstances heretofore employed which after sults, most claysbeing open to certain objecburning are hard andare found to grind with tions, and in many cases the grog is found to dlfiiculty,

possess a foamy and inflated structure, which The ground or granular material, after is objectionable. Attempts have heretofore being separated into the desired sizes by been made to overcome these difliculties by means of suitable screens, is then made up burning the grog at temperatures substaninto chamotte in theusual and wellknown tially higherthan those to be applied during manner. a

the final use of the ware made from the The use of wood, preferably in the form chamotte. However, in such cases the prodof wood flour or finely powdered wood or not did not always have the necessary physiother finely divided wood, in being burned cal and chemical resistance to wear, and out leaves a fine porosity throughout-the enlacked elasticity during the sintering period. tire bricks of the burned grog. 95

40 Further attempts to overcome the difficulty In order to more fully illustrate the inconsisted in the addition (in the making of vention, I give the following example, but it grog) of quartz, quartz sand or ordinary -is to be understood that the inventlon is not sand, being mixed with the clay, thus utilizlimited thereto.

ing the expanding property of the quartz, to To 2000 pounds of finely ground kaolin, mo

overcome the shrinking propertles of the preferablyground sufliciently fine to pass a clay, while exposed to the high temperatures 200 mesh sieve, there is added 500 parts of in the burning operation. Such results howpulverized wood, of a sufficient degree of everwere not entirely satisfactory since the fineness to pass a 70 mesh screen, and one added materials were found to considerably fifth of a ton of ball clay, of a fineness 105 injure the physical properties of the boundsuflicient to pass a 100 mesh screen. The ing agents used in making the chamotte, esmixture is then moistened with a sufficient pecially so when large quantities of quartz or amount of water to render the same plastic, sand were employed. The products proand (after drying) is then subjected to a duced in such prior processes were found to high temperature in a suitable kiln, a tem-. no

be lacking in resistance to high temperatures perature of 2700 F., being found very and were also found to be more or less weak suitable. The plastic mass is preferably finely divided state, material at astrong glowing minuting the product.

'molded into any other desired can be subjected to high pressure in the' molded into the form of bricks or slabs before the burning operation, but it could be shape. It

molding operation, although this is not necessary in all cases. The bricks or slabs can be first dried at. a low temperature, say a temperature between 150 and 220 F., in

order to remove the bulk of the water, before subjecting to the high temperature:

11 some cases, where it is desired to produce' a stronger sintering of the grog mass durin the burning operation, it is advisable to .ad a small amountof colloidal silicic acid, for example about 2 to 10%. Keiselguhr (uncalcined)- can be added for this pur ose if desired.

e proportions and temperatures given are given for the purpose of illustration only, and can be varied between wide limits dependingupon the exact nature of the raw materials used, their purity, fineness and the properties desired in the final product.

Slabs, muflles and the lik made by the use of the present invention will be found to be of very high strength, and will be'found rto be resistant to high temperatures, without warping or cracking.

It wi 1 be understood that in place of the use of wood, I can use various other forms of organic matter of a combustible .nature, which will burn out during the burning operation, to leave the desired porosity. Wood is merely mentioned ness.

I claim 1. A process of producing grog material suitable for use in chamotte which consists in of kaolin, combustia binder, all being in a and water, burnin such heat, emf comorminga plastic mass ble organic matter,

' suitable finely divided state,

on account of its cheapacid, at any grog material which consists kaolin, combus- 2. A process of producing suitable for use in chamotte in forming. a plastic mass of tible organic matter, a binder, all being in a finely divided state, and water, subjecting such mass to high pressure, burning such material at a strong glowing heat, and comminuting the product.

3. A process of producing grog material for use in chamotte which consists in forming a plastic mass of kaolin, combustible organic matter, a binder, all being in a and Water, drying such mass at not substantially over the boiling point of water, burning such material at a strong glowing heat,-a nd comminuting the product. a

4. A process of producing grog material suitable for use in chamotte which consists in forming a tible organic matter, a binder, all being in a finely divided state, and water, burning such material at a temperature approaching 2700 F. V y Y 5. A mode of producing chamotte material which consists in thoroughly mixing clay rich in kaolin, cementitious binder, with enough water to form a plastic mass, the clay being the predominant solid constituent of such mixture, shaping such mixture, burning the same at a white heat, and comminuting the product, and. thereafter binding the comminuted material by adding a binder and again burning the product. I

6. In a recess as in'claim 1, the addition to the initial plastic mass, of hydrated silicic stage prior to the burning 0 eration, whereby the amount of sintering uring burning, is increased and a stronger grog produced.

woody material and a plastic-mass of kaolin, combus- LUDWIG KERN. 

